To develop techniques that will allow for the rapid and quantitative identification of the normal organic components in human urine. These components are separated and identified as acids, neutrals, and bases. The data gathered in this manner will then be used to screen a number of pediatric urine samples looking for subtle indications of inborn errors of metabolism. Concurrent with the above work is the development of computer search and display programs that will aid the chemist in the identification of known compounds found in the urine samples. By using computer techniques the professional help can concentrate on the unusual spectra and on clinical follow-up of results. A second line of research supported on this grant is aimed at the study of sphingolipids by chemical ionization and field desorption mass spectrometry. A field desorption source is being developed which will aid in obtaining spectra of compounds of high molecular weight and polarity. The above research utilizes a Beckman GC-45 gas chromatograph coupled to an AEI-MS-12 mass spectrometer. The data acquisition is handled by a PDP 8/i digital computer.